Investors yanked cash out of emerging-market equity funds at the fastest pace since 2011, underscoring “the first signs of panic” in the markets amid a difficult start to 2014.

That view comes courtesy of Michael Hartnett, chief investment strategist at Bank of America Merrill Lynch, who described the action as a “stampede out of equity ETFs.”

Some $6.4 billion was pulled out of emerging-market equity funds, according to EPFR Global, the largest outflow since August 2011 amid the euro crisis and the downgrade of the U.S. credit rating. For bargain-hunting investors looking to buy near the bottom, they might want to wait longer.

As the chart below shows, emerging-market equity funds would need to witness another $15 billion in outflows over the next two to three weeks before his data would trigger a “contrarian buy signal.”

BofAML Global Research, EPFR Global

The tough times continued Friday: The Dow Jones Industrial Average recently dropped 210 points. The blue-chip average is down by more than 5% for the month.

Mr. Hartnett’s analysis is consistent with what Goldman Sachs reported earlier this week. Over the past decade, there have been 19 times when the MSCI Emerging Markets index dropped by at least 5%, according to Goldman analysts. The average pullback was 12% and lasted about 35 days. The recent emerging-markets turmoil has lasted about a month, during which the index has fallen more than 7%.

And finally, emerging-market debt and equity funds over the past three months have seen outflows of about $42 billion, or about 4% of all assets under management.

Concerns about developing economies from Turkey to Argentina, underpinned by the Fed continuing to scale back its unprecedented stimulus program, left emerging-market assets across the world reeling again. With prices falling and potential losses mounting, some investors rushed to get their money back, EPFR’s data suggest.